The 60 GHz band is an unlicensed band which features a large amount of bandwidth and a large worldwide overlap. The large bandwidth means that a very high volume of information can be transmitted wirelessly. As a result, multiple applications, each requiring transmission of large amounts of data, can be developed to allow wireless communication around the 60 GHz band. Examples for such applications include, but are not limited to, wireless high definition TV (HDTV), wireless docking stations, wireless Gigabit Ethernet, and many others. The IEEE 802.11ad (WiGig) standard is one of the communication standards defined to enable multi-Gb/s wireless communication by utilizing the 60 GHz frequency band and antenna arrays.
In order to facilitate such applications in computing devices, such as laptop computers, smart phones, tablet computers, etc. there is a need to develop integrated circuits (ICs), such as amplifiers, mixers, radio frequency (RF) analog circuits, and active antennas that operate in the 60 GHz frequency range. An RF system typically comprises active and passive modules. The active modules (e.g., a phased array antenna) require control and power signals for their operation, which are not required by passive modules (e.g., filters). The various modules are fabricated and packaged as radio frequency integrated circuits (RFICs) that can be assembled on a printed circuit board (PCB). The size of the RFIC package may range from several to a few hundred square millimeters.
In the consumer electronics market, the design of electronic devices, and thus RF modules integrated therein, should meet the constraints of minimum cost, size, power consumption, and weight. The design of the RF modules should also take into consideration the current assembled configuration of electronic devices, and particularly handheld devices, such as laptop and tablet computers, in order to enable efficient transmission and reception of millimeter wave signals. Furthermore, the design of the RF module should account for minimal power loss of receive and transmit RF signals and for maximum radio coverage.
A typical RF module that operates in the 60 GHz frequency band is designed for transmission and reception of millimeter-wave signals. The RF module includes an array of active antennas connected to a RF circuitry or an IC. Each antenna in the array of antennas may operate as a transmit (TX) and/or receive (RX) antenna.
Specifically, as illustrated in FIG. 1, a millimeter wave antenna 110 is connected through a switch 120 to a power amplifier (PA) 130 and a low noise amplifier (LNA) 140. The PA 130 amplifies transmit signals while the LNA 140 amplifies receive signals. The switch 120 is a single pole, double throw (SPDT) switch. A chip interface (bump′) 150 is an interface point between a board's integrated circuit (e.g., a PCB) and the antenna 110. The control of the switch 120 determines if the antenna 110 is in a transmit mode or a receive mode by a control signal 125 typically provided by a baseband module (not shown). To allow a proper operation of the RF module both the PA 130 and the LNA 140 require a matching network at the chip interface 150.
Although sharing the antennas between transmit (TX) and receive (RX) modes allows reducing the number of required antennas and antenna connections by half, and enables RX/TX reciprocity, still such a design requires an additional SPDT switch to be coupled to each antenna. For an array of antennas including N antennas (N>1), there are N switches.
For consumer electronic devices, such as those described above, there is a significant need to reduce the integrated circuit's area in order to reduce cost and enable a compact solution. Therefore, additional SPDT switches in the RF module increase the total area of the IC and its power consumption. Furthermore, to maximize radio performance, the connection to the antenna needs to introduce minimal signal losses. Thus, directly coupling the antenna to the PA and LNA would introduce significant losses due to lack of proper impedance matching. Furthermore, any design of coupling the antenna to the PA and LNA should meet the constraints which necessitate that the physical dimensions, the power consumption, heat transfer, and cost should be as minimal as possible.
It would be therefore advantageous to provide an efficient IC layout design for an antenna array connectivity that overcomes the disadvantages of conventional layout design.